# CVE-2025-13352: Mattermost GitHub Plugin allows unauthorized GitHub reactions via reaction forwarding hijacking

> CVE-2025-13352: Mattermost GitHub Plugin allows unauthorized GitHub reactions via reaction forwarding hijacking. CVSS 3.0 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2025-13352
Last updated: 2026-10-13T11:10:00Z

- Published: 2025-12-17 12:11 UTC · Updated: 2026-10-13 11:10 UTC · Assigner: Mattermost
- CVSS: 3.0 (CVSS 3.1) · Severity: Low · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N
- EPSS: 0.18%, 7th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-1287

## Description

Mattermost versions 10.11.x \<= 10.11.6 and Mattermost GitHub plugin versions \<=2.4.0 fail to validate plugin bot identity in reaction forwarding which allows attackers to hijack the GitHub reaction feature to make users add reactions to arbitrary GitHub objects via crafted notification posts.

## Affected vendors and products

- Mattermost: Mattermost

## Tracked companies

- [Mattermost](https://rewindex.com/company/mattermost.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2025-13352)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2025-13352)
- [https://mattermost.com/security-updates](https://mattermost.com/security-updates)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2025-13352 · Markdown: https://rewindex.com/cve/CVE-2025-13352.md · JSON: https://rewindex.com/api/v1/cves/CVE-2025-13352 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T04:03:28.390Z